This invention relates to a speed-increasing machine for water, which can be used in a cultivation pool in the aquaculture industry. By utilizing of the rotation of vanes, the circulation of water in the cultivation pool can be improved and the amount of oxygen dissolved in the water can thus be increased.
Water quality and dissolved oxygen in the cultivation pool are the most important factors for aquaculture. For high-density cultivation that is often adopted for saving cost, a large quantity of aquatics exists in a certain area, which may result in massive death of the aquatics when the water quality deteriorates or the dissolved oxygen is insufficient, leading to tremendous damage.
A typical cultivation pool is bounded in a certain area so that the water in the cultivation pool flows relatively slowly, resulting in insufficient dissolved oxygen. Therefore, Machines are often utilized to increase the dissolved oxygen in the water. A typical design available in the market is a small buoyant raft on which a motor is mounted for driving vanes attached to both sides of the raft. A portion of the vanes is above the water level, and the other portion of the vanes is below the water(so-called water wheel). As a result, water in the cultivation pool splashes when the vanes rotate so that water in the deep of the cultivation pool can come into contact with the air above the water level to thereby increase the dissolved oxygen. However, this method can only increase the dissolved oxygen in the area adjacent to the water level, but the dissolved oxygen in deep water is still very low.
With reference to FIG. 11, another kind of oxygen supply machine 5 is shown, which also has a frame 53, floats 531 mounted on both sides of the frame 53 for buoying the frame 53 up, a motor 51 mounted on a top side of the frame 53, and a tank 52 below the frame 53. An output shaft 511 is located in the tank 52, and a vane 512 is mounted on the output shaft. A water inlet 521 is provided in the bottom of the tank 52. A water outlet tube 522 is mounted on a side of the tank 52. A conduit 523 is mounted on a side of the water outlet tube 522. One end of the conduit 523 is extended upwards to above the water level for introducing ambient air into the water outlet tube 522. When the vanes 512 are turned by the motor 51, water in the cultivation pool is sucked by the vanes 512 via the water inlet 512 into tanks 52 and then exits via the water outlet tube 522, creating circulating water currents during which the water flowing through the water outlet tube 522 comes into contact with air in the conduit 523 while creating a suction force for sucking ambient air into the water via the conduit 523. Thus, the dissolved oxygen is increased.
However, after using the aforementioned method to increase the dissolved oxygen in water, it is found that the aquatics intend to gather around the oxygen supply machine 5 because the circulating water currents flow through a small area. In other words, water with high dissolved oxygen is only distributed in a small area around the oxygen supply machine 5 instead of wide, uniform distribution in the cultivation pool. As a result, the dissolved oxygen in the water area away from the oxygen supply machine is still insufficient. Thus, the conventional oxygen supply machine 5 still fails to effectively solve the problems of high-density cultivation.